I was introduced to this video, which is really worth watching. Sure, it's 38mins long but it beats spending 38 minutes trawling through cat pics on Facebook !

All of this can be applied to guitar playing or anything else you're working at. It takes the format of a chat between 3 guys who are successful in their respective fields. Tony Robbins I know of but not the other two. But it's irrelevant.. it's mainly about the different mindset that separates people who take on a task and follow it through and those who give up. If you're struggling with a particular gutiar technique or something, this might give you an insight you didn't previously have. I know I'll be watching it more than once to absorb all the info.